1. Field of the Invention
This invention relates to medical equipment used for the infusion of medications into an intravenous therapy system. More precisely, the invention is a protective sheath for the needle portion of a needle assemblage which is used to inject medication into the Y-site on intravenous tubing during intermittent I.V. therapy. The sheath protects the medical worker from accidental puncture by the intermittent I.V. therapy needle before and especially after the injection of the medication.
2. Description of the Prior Art
Intermittent intravascular injection therapy usually referred to as I.V. therapy is commonly used in hospitals and emergency situations requiring intravascular injection of medications to sustain life and for direct intravascular injection of medications into patients requiring this therapy. Intermittent I.V. therapy needles in use today are disposable units provided in prepackaged sterile containers. Each needle is commonly housed in a full covering rigid plastic cap which must be removed prior to use. After an intermittent I.V. therapy needle has been used, nursing procedure in effect today requires it to be properly disposed of in disposal containers supplied in every patient's room. It is primarily during this stage of the procedure where medical personnel often inadvertently puncture themselves with the used needle. This would not be of particular concern were the patient not infected with some form of contagious disease. The fairly recent occurrence of the disease acquired immune deficiency syndrome, AIDS for short, has now made many medical procedures, especially those involving contact with body fluids of the infected patient, a major concern to medical workers. Intravenous or I.V. therapy systems appear to offer little or no threat to the nurse or technician administrating the therapy. This is not necessarily true because these systems do create a passageway from the patient's circulatory system directly to the I.V. tubing and to the medication injection Y-site port. The potential exists for contamination especially if blood backup occurs within the tubing. Care against accidental self puncture must be exercised by both the nurse and the technician even when a Y-site application is used.
For examination of past art, a patent search was conducted directed towards devices involving protective sheaths for hypodermic needles and particularly for needle protective coverings useful in intravenous therapy systems. Although no protective sheaths particularly for I.V. needle assemblages were seen in patents examined, the following patented devices appeared most pertinent to our invention:
Bower was granted U.S. Pat. No. 2,674,246, dated Apr. 6, 1954, for a rigid open-ended sheath designed to apply pressure to the site of injection to lessen the shock of hypodermic needle penetration to the patient.
Armao was issued U.S. Pat. No. 3,134,380, on May 26, 1964, for an open-ended hypodermic needle which serves to shield the needle from the patients view to avoid alarm.
On Feb. 13, 1979, Alvarez was granted U.S. Pat. No. 4,139,009, for a hypodermic needle assembly with a retractable needle cover. The cover consists of resilient bars which open sideways when compressed, exposing the needle shaft.
U.S. patents issued to Schwartz, U.S. Pat. No. 4,775,369; to Hagen, U.S. Pat. No. 4,735,618; and to Vaillancourt, U.S. Pat. No. 4,725,267, all show collapsible plastic or foam sheaths having apertured distal ends for passage of hypodermic needles.
The U.S. patent issued to Bloch, U.S. Pat. No. 3,354,881, teaches a detachable hypodermic needle protector consisting of a closed ended flexible walled tube containing a chemical guard medium. Both closed ends are self-sealing septums, one end of which the needle is passed through to house the distal end of the needle within the chemical medium. In use, the needle protector is compressed, for example, against the patient's skin forcing the needle through the second septum. Upon removal of the needle from the patient, the needle protector resumes the original shape and the needle is withdrawn back inside, to be chemically treated and reused. This device would not be useful for intermittent I.V. therapy systems.
The Gustavsson device, U.S. Pat. No. 4,564,054, dated Jan. 14, 1986, shows a fluid transfer system having a two piece detachable protective sheath for preventing air contamination when transferring a liquid substance from one vessel to another.
All of the past art devices, excluding the Bloch and Gustavsson patents, show sheaths which provide some measure of structural protection for the needle but contain various apertures or openings which do not maintain the needle in a sterilized environment. This necessitates providing a second protective covering or other means to maintain a sterilized needle. This second protective covering would not only add bulk to the device but would be cumbersome to handle, and would increase the final cost of the unit.
None of the past art devices seen are structured specifically as intermittent I.V. therapy needle sheathes for needles in needle assemblages used at I.V. Y-site ports for medication infusion during intermittent I.V. therapy.